Liftgate with low-liftover liftglass

ABSTRACT

A motor vehicle includes a rear body opening that is closed by an upwardly-pivoting liftgate assembly that itself defines, when in a closed position, a secondary opening whose lowermost portion achieves a height on the vehicle significantly below the vehicle&#39;s beltline. The liftgate assembly also includes a pivotally-mounted liftglass assembly for closing the secondary opening, thereby permitting limited access through the secondary opening into an interior space of the vehicle. When the liftglass assembly is in its closed position, the lowermost edge of the liftglass assembly extends downwardly on the vehicle to a height significantly lower than the vehicle beltline. A raised feature of the liftglass assembly, preferably having a color and surface finish that is coordinated with a painted body surface, defines a step that is substantially aligned with the vehicle beltline to thereby aesthetically substantially continue the vehicle beltline across the rear of the vehicle.

This is a divisional of application Ser. No. 09/910,741, filed Jul. 23, 2001, now U.S. Pat. No. 6,607,231.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to closure panels used to close an opening defined in the rear portion of a vehicle body, as is often found in minivans, sport-utility vehicles, and hatchbacks.

2. Background of the Invention

Minivans, sport-utility vehicles, hatchbacks, and other similar vehicles typically feature a rearward opening defined in the rear portion of the vehicle's body. The prior art generally teaches the use of one or more movable “closure panels” with which to close such openings while otherwise permitting access through the opening to an interior space defined within the vehicle body, such as the interior of the vehicle or a cargo space situated in the rear of the vehicle.

When a single closure panel is used, the single closure panel is typically pivotally mounted to the vehicle body at the panel's upper edge, such that the panel is pivoted upwards to reveal the rear body opening. Such single closure panels are often called “liftgate assemblies” and are often used in conjunction with a continuous weatherstrip secured around the periphery of the rear body opening to thereby obtain a superior weatherseal when the liftgate assembly is in its “closed” position. Because the entire liftgate assembly is pivoted upwards as a single unit to reveal the rear body opening, such liftgate assemblies advantageously provide maximum access to the rear body opening while further featuring a relatively-low “liftover” height, thereby facilitating the ingress and egress, for example, of large or heavy items into the vehicle through the rear body opening. However, such known liftgate assemblies generally require a substantial clearance behind and, perhaps, above the rear of the vehicle in order to be fully deployed to the “open” position, thereby possibly limiting the circumstances under which such maximum access to the rear body opening may be obtained. Moreover, such known liftgate assemblies tend to have greater weight, making such assemblies more difficult to open and, hence, of reduced convenience to a person seeking to gain either quick or a relatively-more-limited degree of access to the rear body opening.

Such known liftgate assemblies usually include a window positioned in the upper portion of the closure panel to improve driver visibility. Typically, the lowermost edge of the window is generally aligned with the vehicle's “beltline,” as defined by the lowermost edges of the windows on either side of the vehicle proximate to the liftgate assembly. The alignment of the liftgate assembly's window with the vehicle beltline is generally considered to provide an aesthetically-desirable visual continuation of the beltline across the rear of the vehicle.

The window of such known liftgate assemblies is either fixed or is pivotally mounted at its upper edge to the upper portion of the liftgate assembly. Such a pivotally-mounted window, also known in the art as a “flipglass” or a “liftglass,” advantageously provides the liftgate assembly with a relatively quick but relatively-more-limited access to the rear body opening. It will be appreciated, however, that the access provided by the liftglass is characterized by an increased “liftover” height, relative to the lower periphery of the rear body opening, due to the alignment of the lowermost edge of the liftglass with the vehicle beltline.

The prior art alternatively teaches use of plural closure panels. For example, the combination of either a lower, downwardly-pivoting, full-width closure panel (often called a “tailgate assembly”) or a pair of lower, laterally-pivoting half-width closure panels (often called “dutch doors”), and a relatively smaller, upwardly-pivoting, full-width closure panel that, in its most simple configuration, is a liftglass. Because each of the plural closure panels is substantially smaller than the single closure panel of an analogous liftgate assembly, each closure panel is likely to be lighter, and less clearance is likely to be required in order to fully deploy a given panel to its open position. However, the lower edge of the liftglass in these oppositely-pivoting multiple-panel embodiments nonetheless remains generally aligned with the vehicle beltline for aesthetic reasons, again providing a relatively increased liftover height when the liftglass alone is pivoted upwards to permit access to the rear body opening.

SUMMARY OF THE INVENTION

It is, therefore, an object of the invention to provide a liftglass assembly, and a method of making such a liftglass assembly, for closing a rear body opening of a motor vehicle, wherein the liftglass assembly includes a lowermost edge that extends below a vehicle “beltline” as defined by a side feature of the vehicle, and wherein the liftglass assembly includes a raised feature that is offset from the lowermost edge and, preferably, substantially aligned with the vehicle beltline to thereby aesthetically substantially continue the vehicle beltline across the rear of the vehicle.

It is also object of the invention to provide a liftglass assembly, and a method of making such a liftglass assembly, for a motor vehicle whose body is painted with a selected body color, wherein the liftglass includes a raised surface having a color that is coordinated with the selected body color.

It is a further object of the invention to provide a liftglass assembly, and a method of making such a liftglass assembly, for a motor vehicle whose body includes a selected surface finish, wherein the liftglass includes a raised surface having a surface finish that is substantially the same as the selected surface finish.

Another object of the invention is to provide a liftgate assembly for closing a rear body opening of a motor vehicle, wherein the liftgate assembly features a liftglass that provides access into an adjacent interior space of the vehicle characterized by a liftover height that is less than that of known liftgate/liftglass assemblies.

Yet another object of the invention is to provide a liftgate assembly for closing a rear body opening of a motor vehicle that features a liftglass whose lowermost edge extends below the vehicle beltline as defined by a side body feature, but which nominally preserves the desirable aesthetic feature of substantially continuing the vehicle beltline across the rear of the vehicle.

Under the invention, a liftglass assembly is provided for closing an opening defined in a body of a motor vehicle, wherein the vehicle includes features defining a vehicle beltline that intersects the opening. The liftglass assembly includes a glass panel adapted to be pivotally mounted on the vehicle body such that the glass panel is movable between a closed position overlying the opening and an open position allowing access to the opening. The liftglass assembly further includes an appliqué permanently secured to a lower portion of the glass panel, the appliqué defining at least a portion of a surface feature that substantially traverses the lower portion of the glass panel in substantial alignment with the vehicle beltline when the glass panel is in the closed position. In a preferred embodiment, wherein the glass panel includes a lowermost edge when in the closed position, the surface feature is a surface contour discontinuity or “step” that is defined, in part, by an edge of the appliqué that is vertically offset from the glass panel's lowermost edge.

By way of example only, in the preferred embodiment, the appliqué is formed of a TPO material whose exterior surface is provided with a “Class 1” finish to generally match that of the vehicle's painted body and, most preferably, has a color that is coordinated with a selected body color of the vehicle. In the preferred embodiment, the appliqué is permanently secured, for example, by a suitable urethane adhesive to an intermediate substrate material that is itself permanently secured to the lowermost portion of the glass panel. The use of the intermediate substrate material and, particularly, the forming of such an intermediate substrate material about or against the lowermost portion of the glass panel, for example, as by injection molding, advantageously provide a substrate surface for supporting the appliqué that is characterized by a desired contour, notwithstanding the presence of any “off-form” tolerance waves in the surface contour of the lower portion of the glass panel.

In accordance with the invention, a method for making a liftglass assembly for a motor vehicle includes defining a surface feature on a lower portion of a glass panel, for example, by inserting at least the lower portion of the glass panel into a mold and overmolding a suitable substrate material about the lower portion of the glass panel to obtain a raised substrate surface; and permanently securing an appliqué to the raised substrate surface. In a preferred method of practicing the invention, in which the raised substrate surface is formed of an injection-molded urethane and the appliqué is formed of a TPO material, the step of permanently securing the appliqué to the raised substrate surface includes surface treating the raised substrate surface and, if necessary, an inner face of the appliqué to facilitate adhesion; and permanently bonding the inner face of the appliqué to the raised substrate surface with a first adhesive.

In accordance with a further feature of the invention, in a preferred method, the step of permanently securing the appliqué to the raised substrate surface includes bonding a relatively-small portion the inner face of the appliqué to the raised substrate surface with a second adhesive, the second adhesive being characterized by a substantially reduced set or cure time relative to the first adhesive. By way of example only, in the preferred method, the first adhesive is a urethane adhesive that is applied to a first portion of the raised substrate surface appliqué that includes its entire periphery, and the second adhesive is a hot-melt adhesive that is applied to several small, spaced portions of the raised substrate surface. The hot-melt adhesive advantageously serves to “fixture” the appliqué to the raised substrate surface during the period in which the first adhesive cures.

In accordance with another feature of the invention, a liftgate assembly is also provided for closing a rear body opening of a motor vehicle that has a vehicle beltline defined by one or more side body features, such as the lowermost portions of one or more side windows. The liftgate assembly includes a closure panel that is pivotally mounted on the vehicle body so as to move between a closed position, in which the closure panel entirely overlies the rear body opening, and an open position permitting access to the rear body opening. A secondary opening defined in the closure panel includes a lowermost portion that extends to a height on the vehicle below the vehicle beltline when the closure panel is in the closed position.

The liftgate assembly further includes a liftglass assembly whose upper portion is pivotally mounted on the closure panel proximate to an upper edge of the liftglass assembly, and whose lower portion includes a raised surface feature, which defines a visual element of the liftglass assembly that is vertically offset from the lowermost edge of the liftglass assembly and, most preferably, is substantially aligned with the vehicle beltline when the liftglass assembly closes the secondary opening to thereby aesthetically substantially continue the vehicle beltline across the rear of the vehicle. In a preferred embodiment, the raised surface feature of the liftglass assembly is defined, at least in part, by an appliqué that is permanently secured to the lower portion of the glass panel and, most preferably, that has a color and surface finish that is coordinated with a selected painted body surface of the vehicle.

The above object and other objects, features, and advantages of the invention are readily apparent from the following detailed description when taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and advantages described herein will be more fully understood by reading an example of an embodiment in which the invention is used to advantage, referred to herein as the Detailed Description of Preferred Embodiment, with reference to the Drawings, wherein:

FIG. 1 is a rear-quarter view in perspective of a motor vehicle with an exemplary liftgate assembly featuring a low-liftover-height liftglass assembly in accordance with the invention;

FIG. 2 is a rear elevational view of the vehicle shown in FIG. 1, showing the exemplary liftgate assembly in the open position;

FIG. 3 is a rear elevational view of the vehicle similar to FIG. 2, but showing the liftglass assembly alone in the open position;

FIG. 4 is a partial side elevational view of the vehicle taken in the direction of Arrow 4 of FIG. 3;

FIG. 5 is a partial sectional view of the liftgate assembly taken along line 5—5 of FIG. 1;

FIG. 6 is a partial sectional view of the liftgate assembly taken along line 6—6 of FIG. 5; and

FIG. 7 is a partially-exploded view in perspective of the liftglass assembly, immediately before the liftglass assembly's appliqué is permanently bonded to a raised intermediate substrate surface molded on the lower portion of the liftglass assembly's glass panel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring to the Drawings, FIG. 1 is a partial rear-quarter view in perspective of a motor vehicle, such as a sport-utility vehicle 10, featuring an exemplary liftgate assembly 12 in accordance with the invention for closing a generally-rectangular opening 14 defined in the rear 16 of the vehicle's body 18. The exemplary liftgate assembly 12 includes a main closure panel 20 that entirely overlies the rear body opening 14. As seen in FIG. 2, the main closure panel 20 is pivotally mounted to the vehicle body 18 proximate to the panel's upper edge 22, for example, by a first pair of laterally-spaced hinges 24. In this manner, the liftgate assembly 12 can be pivoted upward about the axis defined by the hinges 24 to provide full access through the rear body opening 14 to the vehicle's load floor 26. A first pair of pneumatic, “over-center” struts 28 urge the main closure panel 20 toward, and thereafter support the main closure panel 20 in, the open position after the main closure panel 20 is first raised to a threshold, intermediate height.

Returning to FIG. 1, when the main closure panel 20 is in the closed position, the first pair of struts 28 is covered by respective lateral portions 30 of the main closure panel 20 which, in the disclosed vehicle 10, further serve to define the cosmetic, exterior surfaces 32 of the vehicle's “D pillar”. However, it will be appreciated that the invention contemplates configurations in which the lateral portions 30 of the main closure panel 20 provide the liftgate assembly 12 with a substantially-continuous, rearview “cut-line.” Also as seen in FIGS. 1 and 2, the vehicle 10 includes a plurality of windows 34 disposed on either side of the vehicle's body 18. The lowermost edges 36 of each side window 34 cooperate with other side body features to define a “beltline 38” on the vehicle 10.

As best seen in FIGS. 3 and 4, the main closure panel 20 of the liftgate assembly defines a further, secondary opening 40 in the rear 16 of the vehicle 10, through which relatively more-limited access to the vehicle's load floor 26 is obtained. The liftgate assembly 12 further includes a liftglass assembly 42 for closing the secondary opening 40. The liftglass assembly 42 includes an upper portion 44 that is pivotally mounted on the main closure panel 20, again, as by a second pair of laterally-spaced hinges 46. A second pair of pneumatic, “over-center” struts 48 urge the liftglass assembly 42 toward, and thereafter support the liftglass assembly 42 in, the open position after the liftglass assembly 42 is similarly first raised to a predetermined intermediate height. When closed, the lower portion 50 of the liftglass assembly 42 bears against a pair of rubber bumpers 52 mounted on the lateral portions 30 of the main closure panel 20 (the rubber bumpers 52 being illustrated in FIG. 3).

As seen in FIGS. 3 and 4, in accordance with a feature of the invention, the lowermost portion 54 of the liftgate assembly's secondary opening 40 achieves a relative height on the vehicle 10 that is significantly lower than the vehicle's beltline 38. Stated another way, the vehicle beltline 38 may be said to intersect the secondary opening 40 of the liftgate assembly 42 when the liftgate assembly 42 is in the closed position. In this manner, a low “liftover” height is advantageously achieved when the liftglass assembly 42 is raised, thereby providing improved access to the vehicle interior through the secondary opening 40, while the lower portion 56 of the closed liftgate assembly's main closure panel 20 operates to prevent items already placed on the load floor 26 of the vehicle cargo space from falling rearward out of the vehicle 10 when the liftglass assembly 42 is opened. It will also be appreciated that, by significantly lowering the secondary opening's lowermost portion 54 in accordance with the invention, the secondary opening 40 is thereby also provided with a substantially-increased vertical dimension relative to known, beltline-limited liftglass assemblies, while further beneficially reducing the overall weight of the resulting liftgate assembly 12.

In accordance with the invention, the liftglass assembly 42 includes a thin, contoured glass substrate or “glass panel 60” that roughly defines, in plan view, the overall shape of the liftglass assembly 42. The periphery 62 of the glass panel 60 is opaque, for example, as by coating peripheral portions of the glass panel's interior surface 64 with a suitable ceramic paint, to thereby visually define an integrally “framed” window 66 within the liftglass assembly 42. When the liftglass assembly 42 is in the closed position as illustrated in FIG. 2, the opaque periphery 62 of the glass panel 60 overlies the lateral portions 30 of the main closure panel that serve to define the secondary opening 40 while further obscuring from exterior view, for example, the weatherstripping 68 that is disposed on the main closure panel 20 about the secondary opening 40.

Referring again to FIG. 1, the lower portion 50 of the liftglass assembly 42 includes a raised surface feature 70 defining a step 72 that is vertically offset from the lowermost edge 74 of the liftglass assembly 42 and is substantially aligned with the vehicle beltline 38. While the invention contemplates defining the step 72 on the liftglass assembly 42 in any suitable manner, in the exemplary liftgate assembly 42, as best seen in FIGS. 5-7, the raised feature 70 is defined in part by an appliqué 76 that is permanently secured to the lower portion 78 of the glass panel's exterior surface 80, with the desired step 72 being defined by an upper edge of the appliqué 76. Under the invention, the use of a separate appliqué 76 with which to define the raised feature 70 of the liftglass assembly 42 ensures that the raised feature 70 can be provided any desired color and/or surface finish.

In order to ensure that the outer face 82 of the appliqué 76 maintains a desired surface contour when permanently secured to the lower portion 78 of the glass panel 60, notwithstanding the presence of “off-form” tolerance waves in the lower portion 78 of the glass panel 60, an intermediate substrate material 84 is preferably used to define a raised substrate surface 86 on the lower portion 78 of the glass panel 60 that has the desired exterior surface contour, to which the appliqué 76 may then be permanently bonded. In a preferred method, the raised substrate surface 86 is obtained using a low-pressure reaction injection molding (RIM) process, in which a suitable urethane material is overmolded about the lower portion 78 of the glass panel 60.

Preferably, as seen in FIGS. 5-7, the raised substrate surface 86 is itself provided with a stepped peripheral edge 88, within which to receive the slightly-turned periphery 90 of the appliqué 76 to improve both the appearance and durability of the resulting liftglass assembly 42. Further, the intermediate substrate material 84 is preferably overmolded about the lowermost edge 92 and respective lateral edges 94 of the glass panel 60, thereby advantageously providing the resulting liftglass assembly 42 with a molded urethane edge along its lower portion 50. As best seen in FIG. 1, the resulting overmolded lateral edges 95 of the intermediate substrate material 84 are slightly laterally-offset from the respective lateral edges 94 of the glass panel, as seen in FIG. 2, thereby defining a pair of rearview cut-lines on the lower portion 50 of the liftglass assembly 42 that are laterally-offset from the pair of rearview cut-lines defined by the glass panel's lateral edges 94 on the upper portion 44 of the liftglass assembly 42. However, it will be appreciated that the invention contemplates, for example, modification of the lateral edges 94 of the glass panel 60 as necessary, such that the liftglass assembly 42 defines a pair of substantially-continuous rearview cut-lines on the rear of the vehicle 10 when the liftglass assembly 42 is closed over the secondary opening 40.

The raised substrate surface 86 is surface-treated, where necessary or desired, after molding to ensure or enhance appliqué adhesion. By way of example only, where the intermediate substrate material 84 is a molded urethane, the resulting raised substrate surface 86 is preferably cleaned using a suitable cleaner, such as ethyl alcohol applied with a piece of “Scotchbrite”-brand cleaning pad sold by the Minnesota Mining and Manufacturing Company; and then primed with a suitable primer, such as an “Essex”-brand primer sold by DuPont.

While the invention contemplates use of an appliqué 76 formed of any suitable material, in the exemplary liftgate assembly 12, the appliqué 76 is formed of an engineering thermoplastic material, such as an injection-molded “thermoplastic olefin” polymer (TPO). In accordance with a feature of the invention, the outer face 82 of the appliqué 76 is provided with a surface finish that generally matches that of the vehicle's painted body 18 and has a color that is “coordinated with,” i.e., is either the same as or is aesthetically compatible with, a selected body color of the vehicle 10. The color may be integrated into the material of the appliqué 76, as through the use of pigments in the material blend; or through any suitable process by which to provide the outer face 82 of the appliqué 76 with the desired color, including the use of co-molded paint film laminates. It will be appreciated that, to the extent necessary to ensure or enhance the adhesion of a conventional color or clear paint coat to the outer face 82 of the appliqué 76, the outer face 82 of the appliqué 76 may also be surface treated in any suitable manner.

While the invention contemplates any suitable manner for permanently securing the appliqué 76 to the lower portion 78 of the glass panel 60 or preferably, as indicated above, to the contoured, raised substrate surface 86 defined on the lower portion 78 of the glass panel 60, in the exemplary liftgate assembly 12, the inner face 96 of the appliqué 76 is permanently bonded to the raised substrate surface 86 using a suitable urethane adhesive, such as an “Essex”-brand urethane adhesive sold by DuPont.

As illustrated in the partial, exploded view of FIG. 7, in the preferred method, a bead 98 of the urethane adhesive is applied to a first portion 100 of the raised substrate surface 86, whereupon the inner face 96 of the appliqué 76 is pressed against the raised substrate surface 86. To facilitate such permanent bonding, the inner face 96 of the TPO appliqué 76 is preferably surface-treated in any suitable manner to ensure or enhance adhesion. By way of example only, in the exemplary liftgate assembly 12, a thin layer of an adhesion promoter or “primer” is applied as by using a wick applicator to the inner face 96 of the appliqué 76 before bonding with the urethane adhesive. It will be appreciated that the invention contemplates use of any other suitable surface treatment on the inner face 96 of the appliqué 76 including, without limitation, plasma treatment, corona discharge, or surface etching.

In accordance with a further feature of the invention, because the urethane adhesive may require a substantial amount of time within which to cure, the step of permanently securing the appliqué 76 to the raised substrate surface 86 further includes bonding a relatively-small portion the inner face 96 of the appliqué 76 to the raised substrate surface 86 with a second adhesive, the second adhesive being characterized by a substantially reduced set or cure time relative to the first adhesive. Thus, in the preferred method illustrated by the exploded view of FIG. 7, where the bead 98 of urethane adhesive is applied to the first portion 100 of the raised substrate surface 82 that includes its entire periphery, the second adhesive is a hot-melt adhesive 102 that is applied in dollops to several small, spaced portions 104 of the raised substrate surface 86 immediately before the appliqué 76 is pressed against the raised substrate surface 86. The hot-melt adhesive 102 advantageously serves to “fixture” the appliqué 76 to the raised substrate surface 86 during the period in which the urethane adhesive 98 cures.

While an exemplary embodiment of the invention has been illustrated and described, it is not intended that the disclosed embodiment illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. 

What is claimed:
 1. A laminated panel assembly for closing a rear vehicle body opening when it assumes a closed position and for permitting access to the interior of the vehicle body through the opening when it assumes an open position; the panel assembly comprising a glass panel at the rear of the vehicle body with a lower edge extending below a vehicle body beltline, an outer glass panel surface external of the vehicle body interior and an inner glass panel surface on the inner side of the vehicle body interior, the beltline being defined by vehicle body side features; an injection-molded intermediate substrate secured to the outer surface of the glass panel; the injection-molded intermediate substrate defining a raised surface above the outer surface of the glass panel, the raised surface being disposed in a horizontal position in alignment with the vehicle body beltline; the injection-molded intermediate substrate enveloping and being secured to the lower edge of the glass panel at a lower edge of the substrate; an appliqué secured to the substrate in alignment with the vehicle body beltline and defining a continuation of the vehicle body beltline, an exterior surface of the appliqué having a color and finish coordinated with a selected vehicle body color and finish; and the appliqué and the injection-molded intermediate substrate above the lower edge of the glass panel overlying the lower portion of the outer surface of the glass panel; the injection-molded intermediate substrate bridging the lower edge of the glass panel and extending onto the inner surface of the glass panel proximate to the lower edge of the glass panel.
 2. The laminated panel assembly of claim 1, wherein the outer glass panel surface proximate to the lower edge of the glass panel has a first contour, and the raised surface of the injection-molded intermediate substrate has a second contour that differs from the first contour.
 3. The laminated panel assembly of claim 2 wherein the glass panel has lateral edges and the intermediate substrate bridges the lateral edges of the glass panel proximate to the outer glass panel surface to thereby extend onto the inner surface of the glass panel.
 4. The laminated panel assembly of claim 3 wherein each lateral edge of the glass panel defines a respective lateral edge of the panel assembly, and wherein the lateral edges of the panel assembly are laterally offset from the lateral edges of the glass panel proximate to the inner surface of the glass panel.
 5. The laminated panel assembly of claim 1 wherein the glass panel includes a pair of lateral edges connected by the lower edge of the glass panel to thereby define a width dimension of the glass panel extending between the lateral edges; and wherein the appliqué extends substantially across the width dimension of the glass panel.
 6. The laminated panel assembly of claim 1 wherein the appliqué includes an upper edge that extends in generally parallel-spaced relation to the lower edge of the glass panel.
 7. The laminated panel assembly of claim 1 wherein the appliqué is formed of a thermoplastic material.
 8. The laminated panel assembly of claim 1 wherein the raised surface of the injection-molded intermediate substrate includes a stepped periphery; and wherein the appliqué includes a turned peripheral edge adapted to be received in the stepped periphery of the exterior surface of the injection-molded intermediate substrate.
 9. The laminated panel assembly of claim 1 including an adhesive disposed between the appliqué and the outer surface of the injection-molded intermediate substrate, whereby the appliqué is permanently secured to the substrate. 